The owner of the former William Clayton building is delighted that he's made the shortlist to provide new Wellington head office accommodation for the public service.

Balanced Investments director Mike McCombie, who is offering to do a major redevelopment of the Health Ministry's head office, was one of 28 developers vying to offer new or refurbished offices for five government departments.

Of those nine have made the shortlist.

The Government property management centre of expertise issued a request for proposals in August for 60,000 square metres of space for the ministries of health, education, social development, business, innovation and employment, and the Crown Law Office.

The centre, which has now been given Cabinet authority to negotiate with property owners, is refusing to say who else is still in the running.

"The preferred solution involves a combination of existing sites that the Government currently occupies and buildings identified from the tender process," said spokeswoman Bronwyn Saunders.

"We are unable to name the shortlisted sites or the space planned for each Government agency for reasons of commercial sensitivity."

McCombie said he was pleased his proposal had been shortlisted.

His plan offers a $20-$30 million refurbishment and extension of the Clayton building at the top of Molesworth St, which he bought from AMP last year for $14m.

The redevelopment would double the size of the building and increase the net floor space to 16,000sqm.

"It's a significant expansion and upgrade of the building so it will be a big project."

The former Works Ministry head office was built in 1982 and was the first building in the world to be constructed using lead- rubber base isolators to protect it from earthquake damage.

Another developer on the shortlist is Maurice Clark, who is offering a major redevelopment of the long-vacant former Defence House in Stout St. It was also bought from AMP Capital last year for $14m.

He has since done extensive tests to prove its seismic strength and has commissioned design work for a major makeover of the 1940-vintage building.

A surprise omission from the shortlist was the proposed redevelopment of the Bowen Campus, where the Social Development Ministry is now housed.

Precinct Properties chief executive Scott Pritchard said in a statement that the company had been advised that Bowen Campus had been unsuccessful for this round of the Crown's requirements.

"However, we remain very confident in the potential of this site to provide government accommodation in the heart of the parliamentary precinct."

Social Development Ministry head of property Marc Warner said the property management centre of expertise was co- ordinating negotiations in an effort to reduce procurement costs and source quality buildings at a more competitive price.

"This co-ordinated approach will help agencies meet the Government's expectation around reducing the overall building footprint while ensuring better quality work spaces for public servants."